Labour

Question 1

What are the 3 major diagnostic features of labour?

Answer 1

• Regular contractions (at least one every 10 mins)- Cervical changes (effacement, dilatation) ± rupture of membranes

Question 2

What is the latent phase of the first stage of labour?

Answer 2

• From onset of labour (hard to define) until cervix is 4cm dilated- Usually takes ±8 hours, but there is no set time limit

Question 3

What is the active phase of the first stage of labour?

Answer 3

• From 4cm cervical dilatation until delivery- Cervical dilatation should occur at minimum 1cm/hour [1,5cm in multigravidae, 1,2cm in primigravidae]

Question 4

What is the clinical importance if a patient crosses the “warning line” in the first stage of labour?

Answer 4

• Poor progress of stage 1 (i.e. dilating too slowly)- Patient MUST be examined- Reason for poor progress must be identified and addressed

Question 5

What is the clinical importance if a patient crosses the “action” in the first stage of labour?

Answer 5

• Patient must be delivered ASAP- A doctor must evaluate the patient

Question 6

When to suspect cephalopelvic disproportion?

Answer 6

• Head does not descend into pelvic inlet (>2/5 of head above pelvis) AND cervix is dilating

Question 7

How to exclude cephalopelvic disproportion?

Answer 7

• 2/5 or less of head is palpable above the pubic bone

Question 8

Which bones may overlap in moulding?

Answer 8

• Occipital-parietal- Parietal-parietal

Question 9

Grades of moulding

Answer 9

0 Bones normally separated+ Bones touching each other++ Bones overlapping but may be separated with fingers+++ Bones overlapping and inseparable

Question 10

Maternal monitoring in first stage of labour

Answer 10

• 4-hourly assessment: abdominal and vaginal examinations- 2-hourly assessment IF: >8cm; alert line crossed; evidence of maternal or fetal distress

Question 11

Fetal monitoring in first stage of labour

Answer 11

• Every hour in latent phase- Every 30mins in active stage (level 1 patients)- Continuous CTG in all level 2 and 3 patients, or with meconium-stained liquor

Question 12

Fetal monitoring in second stage of labour

Answer 12

• After every contraction- Can alternatively use CTG

Question 13

Active management of third stage of labour

Answer 13

1. Ensure there isn’t an undelivered twin still inside!2. Administer oxytocin (10 IU, given IM)3. Clamp and cut umbilical cord4. Controlled traction of the cord until placenta is delivered

Question 14

At what gestational age will the head engage in a primi gravida?

Answer 14

36/52

Question 15

What are the components of intrauterine resuscitation?

Answer 15

IV fluidsO2 for motherLeft lateral positionTocolyseMonitor fetus

Question 16

Describe the two sources of powers in labour?

Answer 16

Uterine contractions - occur throughout pregnancy, coordinated in labour, 3 in ten minutes, bring about cervical dilatation and aid with descent of the fetus once fully dilated
Maternal explosive effort- bearing down = vasalva maneuvre

Question 17

Describe the lower uterine segment

Answer 17

Lower pole of uterus and cervix that has less muscle, more fibrous CT
Does not contract and retract
Stretches, and stretches rapidly during labour
Begins to form at 28/40

Question 18

What changes occur in the pelvis regarding passage and passenger?

Answer 18

Passage- ligaments become more lax
Has three components- elliptical I let and outlet, with round midcavity
Passenger must follow orientation to each area in order to descend

Question 19

What are the four pelvic shapes?

Answer 19

Gynaecoid
Android
Anthropoid
Platypelloid

Question 20

What are the 5 mechanisms of labour

Answer 20

Descent
Flexion
Internal rotation
Extension
External rotation

Question 21

How does the fetus enter the inlet and why?

Answer 21

Enters looking sideways - occipito-transverse position

Because narrowest diameter of fetal head (BPD) matched to narrowest pelvic diameter (AP diameter)

Question 22

What position does the fetal head assume during descent and why?

Answer 22

Assumes occiput transverse position

Widest pelvis diameter for the widest part of fetal head

Question 23

Why is fetal head flexion important during descent?

Answer 23

Flexion creates smaller structure to pass through the maternal pelvis

Question 24

What is internal rotation?

Answer 24

90 degree rotation in midcavity to a direct occipito-anterior or posterior position to exit elliptical outlet

Question 25

Why does extension of the fetal head occur?

Answer 25

Because the curve of the hollow of the sacrum favours extension as descent occurs

Question 26

What is the purpose of external rotation

Answer 26

To align head with shoulders- shoulders rotate to pass through the pelvic outlet

Question 27

What is restitution?

Answer 27

Return of the fetal head to its transverse position due to rotation of the shoulders into an oblique or frankly AP orientation with further descent

Question 28

What are the causes of poor progress?

Answer 28

Patient- pain, bladder, dehydration
Power- inadequate contractions, ineffective contractions
Passenger- lie, presentation, size, multiple, poor engagement
Passage- no ROM, inadequate pelvis

Question 29

How is CPD diagnosed?

Answer 29

Head 3/5 or more
3+ moulding
Small pelvis

Question 30

What are the three key steps in active management of the third stage?

Answer 30

Administration of oxytocin
Clamping and cutting of umbilical cord
Controlled traction of cord with counter-traction on uterus

Question 31

Why should labour pain be treated?

Answer 31

Exhaustion and pain of labour can desultory in failure of progression of labour
Failed progression can cause maternal exhaustion and/or fetal distress
Personal experience of extreme pain is related to occurrence of postnatal depression

Question 32

What are the pain management options in labour?

Answer 32

Non-pharmacological
Systemic analgesia
Epidural analgesia
Combined spinal epidural analgesia